Abstract

Cosmic strings are predicted to form in a wide variety of models in the early universe but so far, they have never been observed. The most promising way to do so relies on their emission of gravitational wave bursts (at small scale features on the strings called cusps and kinks) which could be detectable by the current generation of interferometers (LIGO-VIRGO) or by the future space interferometer LISA .

In this seminar, I will focus on a particular class of models of cosmic strings in which junctions (points at which several strings are attached) can form. I will show that strings with junctions generally contain many more kinks than ordinary cosmic strings. Consequently, the signal from a network with junctions differs significantly from the predictions made by Damour and Vilenkin for ordinary strings. I will discuss the observability of this signal and the associated constraints on the parameter space of the strings.